This document describes the basic configuration of Sendmail, an open source email routing facility that supports mail-transfer (SMTP).
Install
yum install sendmail
Configure Relay Host
vi /etc/mail/sendmail.cf
# “Smart” relay host (may be null)
DSyour.smtp.server
Testing
Install a mail client.
yum install mail
Send a test message.
echo “This is a testing email.” | mail -s Test email@domain.com